ADC power problem with Quicksilver G4

First time Mac-owner here (though I've used them quite a bit). I just bought a used Quicksilver 733 G4 that seems to be having a weird problem. It powers up and runs fine with VGA, but plugging anything at all into the ADC port (whether a studio display or a Belkin DVI adapter) seems to kill the power. Nothing will turn on at all as long as something's plugged into the ADC port, but as soon as you pull the cable out, it works great.

The ADC port is basically a DVI port with built-in lines for power and USB to the display.

Strange issue...it would be great if you had another video card to test with but it seems to be a video-card related issue.

If the machine refuses to actually power on when the ADC port is connected to soemthing, be careful - there may be some sort of power-related issue that could have devastating effects if left unchecked (it might not be powering up because the breaker on the PSU gets blown due to an over-heavy load/short circuit).

It's the stock card that the machine came with -- I'll have to check the specs to see what it is. What's strange is, if anything at all is plugged into the ADC port, there's no powerup whatsoever. As soon as I pull the cable out, it fires up fine. I can use it all day on the VGA port, but I'd rather have DVI if it's possible.

I tried it on a couple of ADC monitors with no difference and now a DVI monitor with the Belkin ADC-DVI adapter.

I'll check for bent pins. It's a work surplus machine, so I know it's been hooked to a Studio Display before (that's what we have there). Hmmm... thanks for the ideas. Seems it's more complicated than I'd hoped it would be.

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